Enhanced zone-melting recrystallization for crystalline silicon thin-film solar cells

摘要

For zone-melting recrystallization of thin Si films the effects of preheating temperature and focussed lamp intensity on solidification front morphology and defect structure are studied. Subgrain boundaries are the dominating defect type and limit the base diffusion length. In-situ observation of the melt zone shows that cellular growth leads to films with regular spaced subgrain boundaries and low defect density. These films are preferentially (100)-orientated. Crystalline Si thin film solar cells with a random pyramid front side texture were processed from this material resulting in efficiencies up to 12.8%.